diff options
Diffstat (limited to '')
| -rw-r--r-- | libblkid/src/partitions/mac.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/libblkid/src/partitions/mac.c b/libblkid/src/partitions/mac.c new file mode 100644 index 0000000..75a558b --- /dev/null +++ b/libblkid/src/partitions/mac.c @@ -0,0 +1,200 @@ +/* + * mac partitions parsing code + * + * Copyright (C) 2009 Karel Zak <kzak@redhat.com> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * + */ +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <stdint.h> + +#include "partitions.h" + +#define MAC_PARTITION_MAGIC 0x504d +#define MAC_PARTITION_MAGIC_OLD 0x5453 + +/* + * Mac partition entry + * http://developer.apple.com/legacy/mac/library/documentation/mac/Devices/Devices-126.html + */ +struct mac_partition { + uint16_t signature; /* expected to be MAC_PARTITION_MAGIC */ + uint16_t reserved; /* reserved */ + uint32_t map_count; /* # blocks in partition map */ + uint32_t start_block; /* absolute starting block # of partition */ + uint32_t block_count; /* number of blocks in partition */ + char name[32]; /* partition name */ + char type[32]; /* string type description */ + uint32_t data_start; /* rel block # of first data block */ + uint32_t data_count; /* number of data blocks */ + uint32_t status; /* partition status bits */ + uint32_t boot_start; /* first logical block of boot code */ + uint32_t boot_size; /* size of boot code, in bytes */ + uint32_t boot_load; /* boot code load address */ + uint32_t boot_load2; /* reserved */ + uint32_t boot_entry; /* boot code entry point */ + uint32_t boot_entry2; /* reserved */ + uint32_t boot_cksum; /* boot code checksum */ + char processor[16]; /* identifies ISA of boot */ + + /* there is more stuff after this that we don't need */ +} __attribute__((packed)); + +/* + * Driver descriptor structure, in block 0 + * http://developer.apple.com/legacy/mac/library/documentation/mac/Devices/Devices-121.html + */ +struct mac_driver_desc { + uint16_t signature; /* expected to be MAC_DRIVER_MAGIC */ + uint16_t block_size; /* block size of the device */ + uint32_t block_count; /* number of blocks on the device */ + + /* there is more stuff after this that we don't need */ +} __attribute__((packed)); + +static inline unsigned char *get_mac_block( + blkid_probe pr, + uint16_t block_size, + uint32_t num) +{ + return blkid_probe_get_buffer(pr, (uint64_t) num * block_size, block_size); +} + +static inline int has_part_signature(struct mac_partition *p) +{ + return be16_to_cpu(p->signature) == MAC_PARTITION_MAGIC || + be16_to_cpu(p->signature) == MAC_PARTITION_MAGIC_OLD; +} + +static int probe_mac_pt(blkid_probe pr, + const struct blkid_idmag *mag __attribute__((__unused__))) +{ + struct mac_driver_desc *md; + struct mac_partition *p; + blkid_parttable tab = NULL; + blkid_partlist ls; + uint16_t block_size; + uint16_t ssf; /* sector size fragment */ + uint32_t nblks, nprts, i; + + + /* The driver descriptor record is always located at physical block 0, + * the first block on the disk. + */ + md = (struct mac_driver_desc *) blkid_probe_get_sector(pr, 0); + if (!md) { + if (errno) + return -errno; + goto nothing; + } + + block_size = be16_to_cpu(md->block_size); + if (block_size < sizeof(struct mac_partition)) + goto nothing; + + /* The partition map always begins at physical block 1, + * the second block on the disk. + */ + p = (struct mac_partition *) get_mac_block(pr, block_size, 1); + if (!p) { + if (errno) + return -errno; + goto nothing; + } + + /* check the first partition signature */ + if (!has_part_signature(p)) + goto nothing; + + if (blkid_partitions_need_typeonly(pr)) + /* caller does not ask for details about partitions */ + return 0; + + ls = blkid_probe_get_partlist(pr); + if (!ls) + goto nothing; + + tab = blkid_partlist_new_parttable(ls, "mac", 0); + if (!tab) + goto err; + + ssf = block_size / 512; + nblks = be32_to_cpu(p->map_count); + if (nblks > 256) { + nprts = 256; + DBG(LOWPROBE, ul_debug( + "mac: map_count too large, entry[0]: %u, " + "enforcing limit of %u", nblks, nprts)); + } else + nprts = nblks; + + for (i = 0; i < nprts; ++i) { + blkid_partition par; + uint32_t start; + uint32_t size; + + p = (struct mac_partition *) get_mac_block(pr, block_size, i + 1); + if (!p) { + if (errno) + return -errno; + goto nothing; + } + if (!has_part_signature(p)) + goto nothing; + + if (be32_to_cpu(p->map_count) != nblks) { + DBG(LOWPROBE, ul_debug( + "mac: inconsistent map_count in partition map, " + "entry[0]: %u, entry[%u]: %u", + nblks, i, + be32_to_cpu(p->map_count))); + } + + /* + * note that libparted ignores some mac partitions according to + * the partition name (e.g. "Apple_Free" or "Apple_Void"). We + * follows Linux kernel and all partitions are visible + */ + + start = be32_to_cpu(p->start_block) * ssf; + size = be32_to_cpu(p->block_count) * ssf; + + par = blkid_partlist_add_partition(ls, tab, start, size); + if (!par) + goto err; + + blkid_partition_set_name(par, (unsigned char *) p->name, + sizeof(p->name)); + + blkid_partition_set_type_string(par, (unsigned char *) p->type, + sizeof(p->type)); + } + + return BLKID_PROBE_OK; + +nothing: + return BLKID_PROBE_NONE; +err: + return -ENOMEM; +} + +/* + * Mac disk always begin with "Driver Descriptor Record" + * (struct mac_driver_desc) and magic 0x4552. + */ +const struct blkid_idinfo mac_pt_idinfo = +{ + .name = "mac", + .probefunc = probe_mac_pt, + .magics = + { + /* big-endian magic string */ + { .magic = "\x45\x52", .len = 2 }, + { NULL } + } +}; + |